In this work, the radial symmetric vibration modes of thin piezoceramic rings have been analyzed by means of a previously proposed theorfetical model. Both the resonance frequencies and the effective electromechanical coupling factor (keE), as a function of the aspect ratio G between the inner and outer radii of the ring, were computed. The results have shown that the disk structure (G + 0) has only one radial symmetrical mode (with its harmonics), but, for the ring structure (G + l), two different modes are clearly distinguished: the ring mode, which has no harmonics, and a width-like mode, with its harmonics.
Moreover, the results show that the ring structure can be assumed to be definitely reached for G > 0.6. An analysis of the material coupling factor in the ring geometry is reported as well.

In this work, the radial symmetric vibration modes of thin piezoceramic rings have been analyzed by means of a previously proposed theorfetical model. Both the resonance frequencies and the effective electromechanical coupling factor (keE), as a function of the aspect ratio G between the inner and outer radii of the ring, were computed. The results have shown that the disk structure (G + 0) has only one radial symmetrical mode (with its harmonics), but, for the ring structure (G + l), two different modes are clearly distinguished: the ring mode, which has no harmonics, and a width-like mode, with its harmonics.
Moreover, the results show that the ring structure can be assumed to be definitely reached for G > 0.6. An analysis of the material coupling factor in the ring geometry is reported as well.